/* ===================================
   CSS Variables & Design System
   =================================== */

:root {
    /* Light Mode Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --text-primary: #1a1a2e;
    --text-secondary: #4a5568;
    --text-tertiary: #718096;
    
    /* Brand Colors */
    --accent-primary: #3b82f6;
    --accent-secondary: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --accent-gradient-2: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --accent-gradient-3: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    
    /* Status Colors */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    
    /* UI Elements */
    --border-color: #e2e8f0;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Courier New', monospace;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
}

/* Dark Mode */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-tertiary: #94a3b8;
    --border-color: #334155;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.6);
}

/* ===================================
   Reset & Base Styles
   =================================== */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color var(--transition-base), color var(--transition-base);
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
}

a {
    color: inherit;
    text-decoration: none;
    transition: color var(--transition-fast);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* ===================================
   Utility Classes
   =================================== */

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===================================
   Navigation
   =================================== */

#navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

[data-theme="dark"] #navbar {
    background: rgba(15, 23, 42, 0.8);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 800;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
    align-items: center;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link:hover {
    color: var(--accent-primary);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-gradient);
    transition: width var(--transition-base);
}

.nav-link:hover::after {
    width: 100%;
}

.theme-toggle {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-xs);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    width: 40px;
    height: 40px;
}

.theme-toggle:hover {
    background: var(--bg-tertiary);
    transform: rotate(15deg);
}

.sun-icon {
    display: block;
}

.moon-icon {
    display: none;
}

[data-theme="dark"] .sun-icon {
    display: none;
}

[data-theme="dark"] .moon-icon {
    display: block;
}

/* ===================================
   Hero Section
   =================================== */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding-top: 80px;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--accent-gradient-3);
    opacity: 0.05;
    z-index: -1;
}

[data-theme="dark"] .hero-background {
    opacity: 0.1;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    align-items: center;
}

.hero-text {
    animation: fadeInUp 1s ease-out;
}

.hero-greeting {
    display: block;
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.hero-name {
    display: block;
    font-size: 3.5rem;
    font-weight: 800;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
}

.hero-subtitle {
    font-size: 2rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-tertiary);
    line-height: 1.8;
    margin-bottom: var(--spacing-xl);
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.btn {
    padding: 0.875rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    transition: all var(--transition-base);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-secondary);
    border-color: var(--accent-primary);
}

.hero-social {
    display: flex;
    gap: var(--spacing-md);
}

.social-link {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    transition: all var(--transition-base);
}

.social-link:hover {
    background: var(--accent-gradient);
    color: white;
    transform: translateY(-2px);
}

.hero-image {
    animation: fadeIn 1.5s ease-out;
}

.hero-image-wrapper {
    position: relative;
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.hero-image-wrapper::before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: var(--accent-gradient);
    border-radius: var(--radius-xl);
    z-index: -1;
    animation: pulse 3s infinite;
}

.hero-image-wrapper img {
    border-radius: var(--radius-xl);
    display: block;
    width: 100%;
}

/* ===================================
   About Section
   =================================== */

.about {
    padding: var(--spacing-2xl) 0;
    background: var(--bg-secondary);
}

.about-content {
    max-width: 900px;
    margin: 0 auto;
}

.about-text p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.about-intro {
    font-size: 1.25rem !important;
    color: var(--text-primary) !important;
}

.about-highlights {
    display: grid;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.highlight-item {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--accent-primary);
    transition: transform var(--transition-base);
}

.highlight-item:hover {
    transform: translateX(8px);
}

.highlight-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.highlight-item h3 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
}

.highlight-item p {
    color: var(--text-tertiary);
    margin: 0;
}

/* ===================================
   Experience Section
   =================================== */

.experience {
    padding: var(--spacing-2xl) 0;
}

.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--accent-gradient);
}

.timeline-item {
    position: relative;
    padding-left: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.timeline-marker {
    position: absolute;
    left: -8px;
    top: 0;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--accent-primary);
    border: 3px solid var(--bg-primary);
    box-shadow: 0 0 0 3px var(--accent-primary);
}

.timeline-content {
    background: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.timeline-content:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-xs);
    flex-wrap: wrap;
}

.timeline-header h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
}

.timeline-date {
    color: var(--text-tertiary);
    font-size: 0.875rem;
    font-weight: 500;
}

.timeline-company {
    color: var(--accent-primary);
    font-size: 1rem;
    margin-bottom: var(--spacing-md);
}

.timeline-list {
    list-style: none;
    padding-left: 0;
}

.timeline-list li {
    padding-left: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    position: relative;
    color: var(--text-secondary);
}

.timeline-list li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
}

/* ===================================
   Projects Section
   =================================== */

.projects {
    padding: var(--spacing-2xl) 0;
    background: var(--bg-secondary);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

.project-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.project-image {
    position: relative;
    overflow: hidden;
    aspect-ratio: 16 / 10;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.project-card:hover .project-image img {
    transform: scale(1.1);
}

.project-overlay {
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
}

.project-badge {
    background: var(--accent-gradient);
    color: white;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 600;
}

.project-content {
    padding: var(--spacing-md);
}

.project-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.project-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
}

.tech-tag {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    padding: 0.375rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
}

.project-achievement {
    color: var(--accent-primary);
    font-weight: 600;
    font-size: 0.9rem;
    margin-top: var(--spacing-sm);
}

/* ===================================
   Skills Section
   =================================== */

.skills {
    padding: var(--spacing-2xl) 0;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.skill-category {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.skill-category:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.skill-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.skill-category h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.skill-list {
    list-style: none;
    padding: 0;
}

.skill-list li {
    padding: var(--spacing-xs) 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: var(--spacing-md);
}

.skill-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
    font-weight: bold;
}

/* ===================================
   Contact Section
   =================================== */

.contact {
    padding: var(--spacing-2xl) 0;
    background: var(--bg-secondary);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
}

.contact-intro {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    line-height: 1.8;
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.contact-item {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
}

.contact-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.contact-item h3 {
    font-size: 1rem;
    margin-bottom: var(--spacing-xs);
}

.contact-item p,
.contact-item a {
    color: var(--text-secondary);
    margin: 0;
}

.contact-item a:hover {
    color: var(--accent-primary);
}

.contact-form {
    background: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    color: var(--text-primary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-primary);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-status {
    margin-top: var(--spacing-md);
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    display: none;
}

.form-status.success {
    display: block;
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
    border: 1px solid var(--success);
}

.form-status.error {
    display: block;
    background: rgba(239, 68, 68, 0.1);
    color: var(--error);
    border: 1px solid var(--error);
}

/* ===================================
   Footer
   =================================== */

.footer {
    background: var(--bg-tertiary);
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.footer .container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

.footer p {
    color: var(--text-secondary);
}

.footer-links {
    display: flex;
    gap: var(--spacing-lg);
}

.footer-links a {
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--accent-primary);
}

/* ===================================
   Animations
   =================================== */

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 0.5;
    }
    50% {
        opacity: 0.8;
    }
}

/* ===================================
   Responsive Design
   =================================== */

@media (max-width: 768px) {
    .hero-content {
        grid-template-columns: 1fr;
    }
    
    .hero-image {
        order: -1;
        max-width: 300px;
        margin: 0 auto;
    }
    
    .hero-name {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.5rem;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .nav-menu {
        gap: var(--spacing-sm);
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    html {
        font-size: 14px;
    }
    
    .nav-menu {
        display: none;
    }
    
    .hero-name {
        font-size: 2rem;
    }
}